Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
World J Transplant ; 8(1): 13-22, 2018 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-29507858

RESUMO

AIM: To evaluate the effect of a 12-mo supervised aerobic and resistance training, on renal function and exercise capacity compared to usual care recommendations. METHODS: Ninety-nine kidney transplant recipients (KTRs) were assigned to interventional exercise (Group A; n = 52) and a usual care cohort (Group B; n = 47). Blood and urine chemistry, exercise capacity, muscular strength, anthropometric measures and health-related quality of life (HRQoL) were assessed at baseline, and after 6 and 12 mo. Group A underwent a supervised training three times per week for 12 mo. Group B received only general recommendations about home-based physical activities. RESULTS: Eighty-five KTRs completed the study (Group A, n = 44; Group B, n = 41). After 12 mo, renal function remained stable in both groups. Group A significantly increased maximum workload (+13 W, P = 0.0003), V'O2 peak (+3.1 mL/kg per minute, P = 0.0099), muscular strength in plantar flexor (+12 kg, P = 0.0368), height in the countermovement jump (+1.9 cm, P = 0.0293) and decreased in Body Mass Index (-0.5 kg/m2, P = 0.0013). HRQoL significantly improved in physical function (P = 0.0019), physical-role limitations (P = 0.0321) and social functioning scales (P = 0.0346). No improvements were found in Group B. CONCLUSION: Twelve-month of supervised aerobic and resistance training improves the physiological variables related to physical fitness and cardiovascular risks without consequences on renal function. Recommendations alone are not sufficient to induce changes in exercise capacity of KTRs. Our study is an example of collaborative working between transplant centres, sports medicine and exercise facilities.

2.
J Phys Condens Matter ; 24(13): 135401, 2012 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-22392847

RESUMO

This paper deals with the photoluminescence temperature dependence of the zero-phonon lines of Cr(3+) ions in an yttrium aluminium garnet (YAG) matrix. Experimental data were analysed in the framework of electron-phonon coupling in the quadratic approximation and it was found that Cr(3+) ions in the YAG matrix are strongly coupled with lattice vibrations, with a Debye temperature of about 550 K and a value of the quadratic coupling constant of 0.65. The analysis of both homogeneous and inhomogeneous contributions to the photoluminescence linewidth is performed and the results obtained are compared with previously reported data for Fe(3+):YAG and discussed with respect to the different dependences of the two transition metal ions on the crystal field.


Assuntos
Alumínio/química , Cromo/química , Compostos Férricos/química , Fônons , Ítrio/química , Cristalização , Espectroscopia de Ressonância de Spin Eletrônica , Elétrons , Lasers , Medições Luminescentes , Temperatura , Vibração
3.
J Phys Chem A ; 113(50): 13901-6, 2009 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-19842679

RESUMO

High-resolution photoluminescence spectra of Fe:YAG crystals were recorded in the temperature range 10-150 K with different excitation energies, ranging from the band gap energy (6.88 eV) down to selective excitation of Fe(3+) ions (2.40 eV). Iron levels fine structure is found in the zero phonon lines, whose characteristics hint at the presence of the doping Fe(3+) ion in the tetrahedral site with a dynamic Jahn-Teller effect inherent in the (4)T(1) excited states. The analysis of the zero phonon interactions with acoustic phonons was achieved through linear and quadratic electron-phonon coupling models, and the Huang-Rhys factor, the Debye temperature, and the electron-phonon coupling were calculated in the framework of the Debye approximation by including only the Raman two-phonon process. The interactions with lattice phonons were studied, and the results were found to be correspondent to the expected results from previous vibrational data.

4.
J Phys Chem B ; 113(15): 5111-6, 2009 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-19354303

RESUMO

The spectral properties of postdoping prepared type I Rhodamine 6G-silica hybrids were investigated in the case of intentionally large doping (5 x 10(-2) mol/L). Beside expected concentration quenching effects, steady state and time resolved optical spectroscopy measurements displayed the presence of different kind of aggregates, both fluorescent and nonfluorescent. As the irradiation dose on the sample increases, the emission features change: the overall emission increases, the peak of the emission is blue-shifted, and the emission decay time also increases. The modifications of the spectral properties under light excitation are interpreted in terms of dimer to monomer light assisted transformation, and a thermodynamic model based on a monomolecular kinetics is presented.

5.
J Cardiovasc Med (Hagerstown) ; 9(6): 641-52, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18475138

RESUMO

Epidemiological, clinical and laboratory studies have provided definitive evidence that physical activity is able to improve fitness and reduce cardiovascular morbidity and mortality. Moreover, physical exercise also seems to significantly reduce the risk of developing other chronic diseases such as obesity, osteoporosis, diabetes, tumours and depression. Promoting physical activity in the general population is therefore one of the primary objectives of our healthcare institutions. Although the benefits of an active lifestyle have been demonstrated by numerous scientific data, only a few numbers of Italians and Europeans take up regular physical exercise. To promote physical activity, both in the general population and in subjects affected by cardiovascular diseases, the Italian Federation of Sports Medicine, the Italian Society of Sports Cardiology, the Italian Association of Hospital Cardiologists, the Italian Society of Cardiology, the Italian Association of Out-of-Hospital Cardiologists and the Italian Group of Cardiac Rehabilitation have promoted the constitution of a Task Force made up of experts in the fields of sports cardiology. The document produced by the Task Force is intended for healthcare professionals, and deals with the role of physical activity in the prevention and treatment of cardiovascular diseases. It examines the beneficial effects of physical activity on the cardiovascular system, while analysing the possible risks involved and how they can be avoided. The rational principles underlying the prescription of physical activity in the cardiologic setting are described, as are the modalities for prescribing such activity.


Assuntos
Doenças Cardiovasculares/prevenção & controle , Doenças Cardiovasculares/terapia , Terapia por Exercício , Prescrições , Arritmias Cardíacas/terapia , Doença Crônica , Cardiopatias Congênitas/terapia , Insuficiência Cardíaca/terapia , Transplante de Coração/reabilitação , Doenças das Valvas Cardíacas/terapia , Humanos , Hipertensão/terapia , Doenças Vasculares Periféricas/terapia
6.
J Cardiovasc Med (Hagerstown) ; 9(5): 529-44, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18404008

RESUMO

Epidemiological, clinical and laboratory studies have provided definitive evidence that physical activity is able to improve fitness and reduce cardiovascular morbidity and mortality. Moreover, physical exercise also seems to significantly reduce the risk of developing other chronic diseases such as obesity, osteoporosis, diabetes, tumours and depression. Promoting physical activity in the general population is therefore one of the primary objectives of our healthcare institutions. Although the benefits of an active lifestyle have been demonstrated by numerous scientific data, only a few numbers of Italians and Europeans take up regular physical exercise. To promote physical activity, both in the general population and in subjects affected by cardiovascular diseases, the Italian Federation of Sports Medicine, the Italian Society of Sports Cardiology, the Italian Association of Hospital Cardiologists, the Italian Society of Cardiology, the Italian Association of Out-of-Hospital Cardiologists and the Italian Group of Cardiac Rehabilitation have promoted the constitution of a Task Force made up of experts in the fields of sports cardiology. The document produced by the Task Force is intended for healthcare professionals and deals with the role of physical activity in the prevention and treatment of cardiovascular diseases. It examines the beneficial effects of physical activity on the cardiovascular system, while analysing the possible risks involved and how they can be avoided. The rational principles underlying the prescription of physical activity in the cardiologic setting are described, as are the modalities for prescribing such activity.


Assuntos
Reabilitação Cardíaca , Doenças Cardiovasculares/prevenção & controle , Terapia por Exercício , Doenças Cardiovasculares/diagnóstico , Terapia por Exercício/métodos , Humanos , Fatores de Risco
8.
J Phys Chem B ; 110(26): 12932-7, 2006 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-16805594

RESUMO

The quest for a solid-state tunable dye laser can be satisfied by sol-gel prepared organic-inorganic hybrids. A photostability study of porous silica-Rhodamine 6G hybrids prepared via a sol-gel method is presented. The dye molecules can be incorporated into the silica matrix by forming weak or covalent bonds (hybrids of classes I and II, respectively). New class II samples and traditional class I materials prepared by the pre-doping method were synthesized. Samples were characterized by photoluminescence measurements to compare the emission properties and the photostability of the samples. The decay of the fluorescence signal as the cumulative excitation energy increases is reported and interpreted by hypothesizing that the dye molecules can be hosted in different surroundings within the porous glass matrix. The reported photoluminescence and photobleaching features indicate the class II samples as good candidates for solid-state dye lasers.

9.
J Phys Chem B ; 109(3): 1239-42, 2005 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-16851086

RESUMO

We studied the optical properties of sol-gel synthesized porous silica excited by synchrotron radiation in the 4-10 eV range. The spectral and temporal characteristics of the ultraviolet photoluminescence at about 3.7 eV are reported. The UV emission results from the contribution of two different centers: the first one centered at 3.7 eV with a decay time of 2.0 ns and the second one peaked at 3.9 eV with a decay time of 20 ns. We propose to assign the observed luminescence to different interacting surface silanols.


Assuntos
Dióxido de Silício/química , Géis/química , Géis/efeitos da radiação , Luminescência , Fotoquímica , Porosidade , Dióxido de Silício/síntese química , Dióxido de Silício/efeitos da radiação , Síncrotrons , Fatores de Tempo , Raios Ultravioleta
10.
J Phys Chem B ; 109(10): 4448-54, 2005 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-16851516

RESUMO

TiO(2) nanoparticles are obtained by combining a sol-gel preparative route with hydrothermal aging steps, performed in mild conditions, of varying time lengths. Both aged and un-aged samples are thermally treated at 300 and 600 degrees C, for the same length of time. The crystal structures, the phase composition, and crystallite sizes are analyzed by powder X-ray diffraction. Raman spectra of anatase nanocrystals with average sizes of 7-10 nm are reported and the correlation between the Raman band shape of the main feature at 144 cm(-1) and the crystallite size is discussed. Nitrogen physisorption by Brunauer-Emmett-Teller (BET) method is adopted to evaluate the particles surface area and mesopore size and size distribution. The role played by the hydrothermal step in affecting the physicochemical properties of the powders is discussed also with respect to the H(2)O/TiO(2) interactions as apparent from Raman spectroscopy investigations of the O-H stretching range (3000-3800 cm(-1)).

11.
J Phys Chem B ; 109(30): 14441-4, 2005 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-16852817

RESUMO

The optical properties of sol-gel synthesized porous silica excited by synchrotron radiation in the 4-10 eV range of samples with different porosity at 8 K and room temperature are reported. The analysis of the ultraviolet photoluminescence indicate the contributions of two different emitting centers. The spectral and temporal characteristics of the two luminescence bands are reported: emission peaks at about 3.7 and 4.0 eV, excitation channels around 5.4-5.7 and 6.2-6.5 eV, and mean lifetimes of about 17 and 2 ns, respectively. The analysis of the optical properties in samples with different porosity allows us to propose a silanol-related model for the two centers.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...